The purpose is to elicit molecular details of conformational kinetics in polypeptides and DNA. An eventual aim is to understand the mechanisms and pathways of DNA double helix formation, of protein folding, and of their denaturation and renaturation. A mathematical model of the rates for passing between the various configurational states was previously formulated. Molecular states are specified for each residue as one of a small number of conformations. The effects of an external field in perturbing conformational equilibria have been studied. Local compositional variations provide portions of biological macromolecules which are particularly susceptible to such external effects. In the case of an electric field, these effects can be direct or can be mediated by changes in counterion distributions.